$flow — Workflow Directive

Complete Path Reference

Complex Scenarios

Scenario 1 — Versioned Audit Trail

Stamp every audit event with the exact workflow version that processed it:

// Audit log node — structured record
{
  "event":       "workflow_completed",
  "workflowId":  "{@ $flow.current.id }",
  "workflowName":"{@ $flow.current.name }",
  "version":     "{@ $flow.current.version }",
  "executionId": "{@ $exec.executionId }",
  "timestamp":   "{@ $ctx.now }"
}

Scenario 2 — Dynamic Email Subject Based on Workflow Name

Build a notification subject that includes the workflow and node context:

Scenario 3 — Detecting Sub-workflow Context

A shared utility workflow behaves differently when called as a sub-workflow vs. a standalone trigger:

// IfCondition: adjust logging verbosity for sub-workflows
{@ $js`
const isSub = context.flow.current.isSubWorkflow;
// When called from parent, reduce log noise
return isSub ? 'minimal' : 'full';
` }

// In the log node: append parent execution only when applicable
{@ $js`
if (context.flow.current.isSubWorkflow) {
  return 'Parent: ' + (context.exec.parentExecutionId || 'unknown');
}
return 'Top-level execution';
` }

Scenario 4 — Node Type Routing in Generic Error Handler

A catch block uses node type to pick the right recovery strategy:

// CatchBlock: route to different recovery nodes based on failing node type
{@ $js`
const nodeType = context.flow.node.type;
if (nodeType === 'HttpRequest') return 'http_retry';
if (nodeType === 'EmailSend')   return 'email_fallback';
if (nodeType === 'DbQuery')     return 'db_circuit_break';
return 'generic_error';
` }

Scenario 5 — Parallel Thread Status in Summary Node

After a ParallelFork, a merge node uses thread info to build a summary:

// Merge node — confirm both threads completed
{
  "mergedFrom": [
    { "thread": "{@ $flow.thread.id }", "parallel": {@ $flow.thread.isParallel } }
  ],
  "workflow": "{@ $flow.current.name } v{@ $flow.current.version }"
}

Scenario 6 — Workflow Tag-Based Feature Toggling

Check workflow tags at runtime to decide whether to enable a new processing path:

// IfCondition: only run new pricing engine if workflow is tagged "beta"
{@ $js`
const tags = context.flow.current.tags || [];
return tags.includes('beta') && tags.includes('pricing-v2');
` }
// true → route to new pricing engine branch
// false → route to stable pricing engine

Common Errors